For his leadership in separations science and technology; for improving nuclear fuel recycling and waste removal; and for leading the development process that was instrumental in the cleanup of waste at the Savannah River Site.
For environmental-effects research related to energy technologies and their use, focusing on the impacts of climate and atmospheric changes on the physiology, growth, and biogeochemical cycles of North American forest ecosystems.
For pioneering research and development of new materials for advanced energy technologies, including materials for (a) the storage of nuclear waste, (b) the solid-state generation of electrical power directly from heat, and (c) the lossless transport of electricity.
For pioneering research in disturbance and landscape ecology and in modeling of land-use change with its implications for global changes, which have influenced environmental decision making on a worldwide scale.
For internationally recognized contributions in distributed and cluster computing, including the development of the Parallel Virtual Machine and the Message Passing Interface standard now widely used in science to solve computational problems in biology, physics, chemistry, and materials science.
For pioneering research in ecosystem theory, ecological modeling, error analysis, hierarchy theory, and landscape ecology and for the development of basic applications in risk assessment and regional environmental analysis.